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authorPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>2023-07-31 17:13:33 +0800
committerVinod Koul <vkoul@kernel.org>2023-08-11 07:59:25 +0100
commite66f91a2d10b9a25eedcaddee9d6f08c8132760a (patch)
tree8588630b9772f762501efe2ffb93cbea74736f2b /drivers/soundwire/sysfs_local.h
parent39d80b0e5fed2c32f66093fead626358b7106974 (diff)
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soundwire: intel_auxdevice: add hybrid IDA-based device_number allocation
The IDA-based allocation is useful to simplify debug, but it was also introduced as a prerequisite to deal with the Intel Lunar Lake hardware programming sequences: the wake-ups have to be handled with a system-unique SDI address at the HDaudio controller level. At the time, the restriction introduced by the IDA to 8 devices total seemed perfectly fine, but recently hardware vendors created configurations with more than 8 devices. Add a new allocation strategy to allow for more than 8 devices using information on the type of devices, and only use the IDA-based allocation for devices capable of generating a wake. In theory the information on wake capabilities should come from firmware, but none of the existing ACPI tables provide it. The drivers set the 'wake_capable' property, but this cannot be used reliably: if the driver probe happens *after* the enumeration, then that property is not initialized yet. Trying to modify the device_number on-the-fly proved to be an impossible task generating race conditions left and right. The only reliable work-around to control the enumeration is to add a quirk table. It's ugly but until platform firmware improves, hopefully as a result of MIPI/SDCA stardization, we can expect that quirk table to grow for each new headset or microphone codec. Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Reviewed-by: Rander Wang <rander.wang@intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Link: https://lore.kernel.org/r/20230731091333.3593132-4-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/soundwire/sysfs_local.h')
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